1. Field of the Invention
The present invention relates to a disk device for use with personal computers, audio equipment, etc., into which is loaded a disk package accommodating different types of disks together, such as CD, CD-ROM, DVD and PD, and which selects one of the disks from the package and drives it when the package is loaded.
2. Description of the Related Art
There are proposed a variety of optical disk media. CD (Compact Disk) and CD-ROM (CD--Read Only Memory) are disks of pit modulation type, and CD-R (CD--Rewritable) is a disk capable of recording data once. PD (Power Disk) is a disk of phase changing type capable of recording/playback (reproduction), and MO (Magneto-Optical Memory) and HS (Hyper Storage) are disks of magneto-optical type capable of recording/playback. Further, as large-capacity disks used for audio, video and computer data, there are known DVD-ROM (Digital Versatile Disk--ROM) of pit modulation type and DVD-RAM (DVD--Random Access Memory) of phase changing type capable of recording/playback. MD (Mini Disk) is also known as a small disk of magneto-optical type capable of recording/playback which is used with audio equipment and computers.
Disk devices for driving such disks are grouped into two types. In one type, only one selected from various disks is loaded in the disk device. In the other type represented by a CD changer, for example, a plurality of disks of the same type are loaded in the disk device and one of those disks is selected and driven for playback.
Recently, there have also been proposed disk devices which include disk driving means capable of driving both CD and DVD and are adaptable for loading of both CD and DVD.
For disk devices adaptable for different types of disks, however, most devices are designed to load CD or DVD one by one therein individually and devices permitting different types of disks to be loaded therein at the same time have not yet been proposed. In particular, disk devices adaptable for simultaneous loading of both a disk exclusive to playback and a recordable disk, such as represented by a combination of CD or CD-ROM and DVD-RAM or a combination of DVD-ROM and DVD-RAM, have not been conceived. Taking into account versatile utility of optical disk media in future, i.e., versatility of computer software and an increase in capacity of demanded data, there exists a need for a disk device which permits different types of disks to be loaded therein together.
In the conventional disk devices into which different types of disks, such as CD or DVD, are loaded separately, the type of the loaded disk is determined with an optical head by reading the TOC data of the disk, or detecting a difference in thickness from the cover surface to the recording surface of the disk, or detecting the track density. This gives rise to a problem that a long time is required for the device to, after loading of a disk, determine the type of the disk and come into the playback operation, etc.
Further, assuming a disk device into which both a disk exclusive to playback, e.g., DVD-ROM, and a recordable disk, e.g., DVD-RAM, can be loaded, a problem is expected to occur in that if an error takes place in determining the type of the loaded disk, the disk device may take DVD-ROM as DVD-RAM erroneously and apply laser power for recording to the DVD-ROM, thereby destroying the data recorded in the DVD-ROM.